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xeno
09-17-2003, 05:27 PM
Hi there, I have a question i thought id ask!
How did they create the effect for the invisible man in League of extraordinary men? (or any other imvisible man films for that matter)
What i mean is, how do u create just a face, which can also be viewd from the back, for instance, when u stand behind the invisible chracter, u see his face but backwards.

Normally i would say, u just paint the face of the actor white, and the rest blue or green. But if u do that and key out the blue, u can only see the white of the face when u film in front of the man, but how can u make that viewed from the side, u can still see a part of his face that would normally be obscured by the blue painted rest of the head?

And how can u create that effect when the camera moves? When the camera is just standing still one would simply shoot a picture of the empty room and place that one behind the keyed out actor. But when the camera moves, how do u create the background behind the man?

I hope that any of u can understand this, its a bit hard to explain lol!

tnx loads in advance!
Joel Hooks
09-17-2003, 06:13 PM
Just a guess, but some sort of blue/green body suit would be my first thoughts...
xeno
09-17-2003, 06:43 PM
yes, but if ud move the camera behind the actor then u wouldnt see the painted face. But how can u make it so that u can still see that painted part of the face, but viewed from the back..for example, when the camera is moving around the actor and we slowly move from front view to backview
Joel Hooks
09-17-2003, 06:59 PM
Then I am going to take a guess and say that the face would be digital replacement camera matched to the real face.

I see what you're saying, I am just guessing here - so don't take my comments as having any real value ;)
xeno
09-17-2003, 07:17 PM
hmm, could be, but then how do u key something out and make the background come through the keyed out section when the camera is moving and u dont have a static background?

i really want to know, since im trying to get this into a school project
Amyd
09-17-2003, 08:32 PM
There are lots of different options, depending on the particular shot and, naturally, on the budget.

You can shoot everything with a motion control rig, for instance. That way you simply duplicate whatever camera move you have without the actor and then difference key it, roto it & voila, you have everything you need.

You can also do a lot of roto, using frames from behind and after, to construct from pieces a clean plate, without the need to shoot a special pass. Naturally, this is very work-intensive, and may not be possible if the movement is too complicated, there is too much perspective shift or the background is too detailed.

There is always the option of taking room surveys (photos & measurement) and then reconstructing the location in 3D and then creating the background camera move in CGI. Also very work intensive, and it is hard to get it to look exactly right and natural, but it is used quite often.

And like lowdown said, it is a very common option as well to simply do a CGI face (either scanned or modelled from references) and then shoot the background moves without actor, then place it in the shot.

Haven't seen the movie you mentioned yet, so I cannot tell you which of the above was used there - though my guess would be a combination thereof.

Cheers,
Andrei
xeno
09-17-2003, 08:47 PM
tnx loads! so i guess that i really do need either a cam rig or a really good roto job...i was kinda hopin thered be an easier trick for this :)

Oh well, back to the drawing board again!
azazel
09-17-2003, 09:24 PM
erhm... there was article on cgchannel about LXG while ago, and there was some info on invisible man in there ;). ..
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